Visu-Lok® Blind Fastening System The Visu-Lok® system is a blind fastener that provides high shear, tensile, fatigue, and self-locking capabilities. Unlike conventional nut and bolt combinations, the Visu-Lok blind bolt can be completely installed, and fully verified, from one side of the structure. When installed, the Visu-Lok forms a solid, blind side head, with minimum preload levels guaranteed. Manufactured in 1/16” increments, Visu-Loks have an operational grip range of .062”.

The Visu-Lok family includes the Visu-Lok II, which utilizes a disposable drive nut. This drive nut allows for the use of only two installation nosepieces for installation of all fastener sizes. A tapered version of the Visu-Lok is ideally suited for extreme or severe fatigue applications. It combines one-sided installation with the advantages of tapered, interference fit. The tapered Visu-Lok also offers the highest possible fatigue life and uniform high preload values, as well as positive self-locking characteristics. Since it distributes the overall load more evenly, fewer fasteners may be required. Tapered Visu-Loks are also used for aircraft modifications or repairs.

The Visu-Lok system uses common installation tools at standard air pressure levels. Alcoa Fastening Systems Assembly Tool Systems offers a wide selection of both hand and power installation tools. Visu-Lok fasteners are available in a wide range of materials, including Aluminum, Alloy Steel, H-11, Corrosion Resistant Steels, Inconel Nickel-Chromium Alloy, and Titanium. Visu-Loks are produced in flush and protruding head styles for shear and tension applications. Various finishes are available.

Other variations of the Visu-Loks are oversize and close-tolerance (interference fit) configurations.

Both unified and metric products are available. Visu-Lok blind fasteners are covered by “NAS” standards.

Typical Visu-Lok applications include fixed and rotary-wing, commercial and military aircraft.

Visu-Lok® is a registered trademark of Monogram Aerospace Fasteners, Inc.